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. 2021 Apr 8;18(8):3912.
doi: 10.3390/ijerph18083912.

Detection of Free-Living Amoebae and Their Intracellular Bacteria in Borehole Water before and after a Ceramic Pot Filter Point-of-Use Intervention in Rural Communities in South Africa

Clarissa van der Loo  1 , Catheleen Bartie  2 , Tobias George Barnard  1 , Natasha Potgieter  3
Affiliations

Detection of Free-Living Amoebae and Their Intracellular Bacteria in Borehole Water before and after a Ceramic Pot Filter Point-of-Use Intervention in Rural Communities in South Africa

Clarissa van der Loo et al. Int J Environ Res Public Health. .

Abstract

Free-living amoebae (FLA) are ubiquitous in nature, whereas amoeba-resistant bacteria (ARB) have evolved virulent mechanisms that allow them to resist FLA digestion mechanisms and survive inside the amoeba during hostile environmental conditions. This study assessed the prevalence of FLA and ARB species in borehole water before and after a ceramic point-of-use intervention in rural households. A total of 529 water samples were collected over a five-month period from 82 households. All water samples were subjected to amoebal enrichment, bacterial isolation on selective media, and molecular identification using 16S PCR/sequencing to determine ARB species and 18S rRNA PCR/sequencing to determine FLA species present in the water samples before and after the ceramic pot intervention. Several FLA species including Acanthamoeba spp. and Mycobacterium spp. were isolated. The ceramic pot filter removed many of these microorganisms from the borehole water. However, design flaws could have been responsible for some FLA and ARB detected in the filtered water. FLA and their associated ARB are ubiquitous in borehole water, and some of these species might be potentially harmful and a health risk to vulnerable individuals. There is a need to do more investigations into the health risk of these organisms after point-of-use treatment.

Keywords: amoeba-resistant bacteria (ARB); borehole water; ceramic filter; free-living amoeba (FLA); point-of-use intervention; rural communities.

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Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
Central, large water storage tank (A), with close-up photo of tap (B).
Figure 2
Figure 2
A tap connected to a windmill.
Figure 3
Figure 3
A communal tap outside the households.
Figure 4
Figure 4
Jug used for water collection.
Figure 5
Figure 5
Ceramic pot device.
Figure 6
Figure 6
A 1000× magnification of (A) free-living amoebae (FLA) trophozoites; (B) double-walled Acanthamoeba spp. cysts, and (C) Vermamoeba spp. trophozoites.
See this image and copyright information in PMC

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